The advancement of information and computer technology has created significant impact on various aspects of our life including education. It has become a global trend to use e-Learning resources as a medium for learning and teaching both inside and outside the classroom. With the increasing popularity of e-Learning, a large variety of digital resources including e-text and e-textbooks have been developed.
Nevertheless, like the traditional learning materials, one difficulty faced by educators and parents is that it is generally difficult to evaluate whether the e-resources are of the appropriate level to meet the specific teaching or studying requirements. It is also difficult to determine whether the content of e-resources fulfill a particular learning purpose as desired. Most of the time, assessment is made according to the experience of the educators and the parents, which could be easily influenced by subjective views and therefore could be inaccurate.